OPSONINS 283 



latter view. Dean, 1 however, showed that not all of the normal opsonina 

 are thermolabile and that, by absorption experiments, bacteria treated 

 with normal sera could be prevented from taking up opsonins from 

 immune sera. These facts seem to point strongly toward the identity of 

 normal and immune opsonic substances. 



Further study of the opsonins has led to numerous other questions 

 regarding their structure, their relation to other immune bodies, etc., 

 which are largely still in the stage of controversy, and for which the 

 original monographs must be consulted. 



The controversial questions may be briefly reviewed as follows: 



As stated above, Wright believed originally that the bodies dis- 

 covered by him in normal sera, the "normal opsonins," in other words, 

 were distinct bodies that could not be identified with either the comple- 

 ment or antibodies present in serum. Neufeld and Hiine, 2 Levaditi and 

 Inmann, 3 and others, on the other hand, maintain that the opsonic 

 action of normal serum, at least, is intimately related to the complement 

 contents of such serum. 



They base this contention not only upon the thermolability of normal 

 opsonins, but also upon the fact that opsoniii may be removed from 

 normal serum at the same time as complement by the method of com- 

 plement fixation, detailed in another section (see pp. 245 and 261) * 



The contention of Wright that the thermostable opsonic substances 

 of immune serum are distinct bodies, not identical with the ambocep- 

 tors, is supported by the work of Hektoen, 5 Neufeld and Topfer,* 

 and others. The problem, however, can by no means be regarded as 

 finally settled, since other workers, notably Levaditi, are inclined to 

 identify the immune opsonins with lytic amboceptors. 



As to the structure of the opsonic substances, moreover, dif- 

 ferences of opinion still exist. Hektoen and Ruediger 7 who have 

 investigated the question attribute to opsonins a complex constitution. 

 They believe them to possess a thermostable haptoohore group 

 and a thermolabile " opsonophore " group and that heating beyond 

 a definite temperature converts the opsonins into opsonoids by 



1 Dean, Proc. Roy. Soc., London, Ixxvi, 1905. 



2 Neufeld and Hune, Arb. a. d. kais. Gesundheitsamt, xxv. 



* Levaditi and Inmann, Compt. rend, de la soc. de biol., 62, 1907. 

 Levaditi, Presse m&licale, 70, 1907. 



* Hektoen, Jour, of Inf. Dis., iii, 1906. 



Neufeld und Topfer, Cent. f. Bakt., xxxviii, 1905. 

 Hektoen and Ruediger, Jour, of Inf. Dis., ii, 1905. 



